Overview of in vitro assessment of immunotoxicity

Over the last two decades, substantial progress has been made in the field of in vitro immunotoxicology. Unfortunately, only few in vitro methods have been adopted for routine testing for skin sensitization, while for immunosuppression little has changed in the current practice. In the latter case, current guidelines still rely on animal tests, which include general immune endpoints in repeated dose studies and trigger dedicated tests on a case-by-case basis. To date, only US-EPA requires functional tests for the registration of pesticides. Several in vitro approaches have been proposed for screening and prioritization of chemicals for in vivo testing, which may offer opportunities to replace animal testing in the near future. From the improved understanding of the pathways underlying immunotoxicity induction, new approaches are emerging which should be applied for assessment of the immunomodulatory properties of chemicals and included in integrated testing strategies. The purpose of this review is to give a general overview of in vitro immunotoxicology, dedicated contributions by experts are part of the Special Issue 'Opportunities and challenges for in vitro assessment of immunotoxicity'.